Web splicing apparatus

ABSTRACT

In a machine which applies a web as an outer coating to a length of pipe, the web being applied under tension, the machine including a web supply spindle and means defining a web delivery path from the spindle to the length of pipe, the improvement comprising retarding means disposed along the web path intermediate the spindle and the pipe operative to exert a retarding force on web delivered to the pipe, and a web splicing facilitator disposed along the web path intermediate the spindle and the retarding means. The web splicing facilitator is operative to stabilize a terminal portion of a first length of web thereby permitting splicing of that terminal portion to an initial portion of a second length of web.

o g United States Patent 1191 1111 3,873,396 Rice Mar. 25, 1975 [54] WEBSPLICING APPARATUS 3,218,22l 11/1965 Burns 161/36 3,374,963 3/1968 C t'242 58.4 [75] Inventor: Claude Bamsdan, Okla- 3,505,148 4/1970 148:1;156 /36l [73] Assignee: The Kendall Company, Boston,

Mass. Primary ExaminerWi1liam A. Powell Filed Mar 1973 AssistantExaminer-Brian J. Leitten [21] Appl. No.: 340,262 [57] ABSTRACT 1n amachine which applies a web as an outer coating 52 us. Cl 156/392,156/157, 156/162, to a length of Pipe, the Web being applied under56/188. 56/195, 156/392, 156/4297 sion, the machine including a websupply spindle and 156/432 [56/494, 156/504 242/585 means defining a webdelivery path from the spindle 511 1111. C1 B65h 81/00 to the length ofPipe, the improvement Comprising [58] Field of Search 156/157, 159,187,188, tardihg means disposed along the Web P intermedi- 156190 191,192 392, 428, 429, 5 504 ate the spindle and the pipe operative to exerta re- 195 494 162 6 138/129 tardi'ng force on web delivered to the pipe,and a web 5 5 75.2 splicing facilitator disposed along the web pathinter- 1 mediate the spindle and the retarding means. The web 5References Cited splicing facilitator is operative to stabilize aterminal UNITED STATES PATENTS portion of a first length of web therebypermitting splicing of that terminal portion to an initial portion of2,724,426 11/1955 Bell et a1 156/159 3 Second length of web. 2,863,20412/1958 T1mothy et a1. 3,024,157 3/1962 Beerli 156/504 8 Claims, 2Drawing Figures PATENTED AR 2 51975 sum 1 0F 2 WEB SPLICING APPARATUSBACKGROUND OF THE INVENTION This invention relates to apparatus of thetype which applies a web as an outer wrapping to a length of pipe.

To protect underground pipelines (e.g., natural gas or oil transmissionlines) against damage due to corrosion, it is necessary to apply ananti-corrosive coating to the exterior surface of the pipe. In recentyears, this coating has often taken the form of one or more layers ofplastic tape wound in an overlapping fashion around the exterior of thepipe. For the background of this technique of pipe protection, thereader is referred to Hielema US. Pat. No. 3,700,520 issued Oct. 24,1972.

The application of the tape to the pipe may take place on a continuousbasis using over-the-ditch apparatus at the installation site or, usingsomewhat different apparatus, at a fixed location with subsequenttransport of the pipe to the installation location. It is the lattersituation to which the present invention is directed.

Typical apparatus for the application of tape to pipe in a fixedlocation provides for the movement of the pipe through or past theapparatus with translation and rotation of the pipe drawing the tape ortapes onto the pipe from fixed tape supply rolls.

It is a principal object of the present invention to provideimprovements in apparatus of the type which applies a web to a movinglength of pipe which will increase the efficiency of such apparatus. Itis a further object to provide improvements which increase theproduction of the rate of the apparatus while maintaining operatorsafety.

SUMMARY OF THE INVENTION As mentioned above, the invention comprisesimprovements in apparatus which applies a web as an outer coating to alength of pipe, the web being applied under tension and the apparatusincluding a web supply spindle and means defining a web delivery pathfrom the spindle to the length of pipe. In one aspect of the invention,the improvement comprises retarding means, disposed along the webdelivery path intermediate the spindle and the length of pipe, operativeto exert the retarding force on the web delivered to the length of pipe.A web splicing facilitator is also provided and is disposed along theweb delivery path intermediate the spindle and the retarding means. Thefacilitator is operative to stabilize a terminal portion of a firstlength of web, thereby permitting splicing of that terminal portion toan initial portion of a second length of web.

In another aspect, the improvement comprises such retarding meansdisposed along the web delivery path intermediate the spindle and thelength of pipe, in combination with a web stabilizer also disposed alongthe web delivery path and located intermediate the spindle and retardingmeans. The stabilizer includes a web accumulator comprising aweb-storing enclosure and web drive means upstream along the webdelivery path from the enclosure. The web drive means supply web to theenclosure at a rate which is faster than the rate at which the web isapplied to the length of pipe. Thus, by operation of the web drive meansfor an appropriate period of time prior to the exhaustion of a firstsupply roll of web, a quantity of web will be accumulated in arelatively slack condition, with the retarding means, downstream of theaccumulator, maintaining the necesssary web tension for properapplication to the length of pipe. The accumulated web thus provides acontinuous supply for wrapping the pipe, while the tail of web upstreamof the accumulator remains stationary (thus stabilized), permitting aneat and safe splice to a fresh supply roll of web. In preferredembodiments of this aspect of the invention, the enclosure has a webentrance slot, a web exit slot, a depth less than twice the width of theweb, and a height and width sufficient to contain therein a plurality ofslack web loops; the drive means comprise a pair of rolls providing anip through which the web passes, one of the rolls being driven by amotor; and the retarding means comprise a drum around which the web istrained and brake means for inhibiting the rotation of the drum.

In another aspect of the invention, the stabilizer comprises a splicingmember which includes a pressure receiving surface disposed along theweb delivery path intermediate the spindle and the retarding means, thesurface being elongated in the direction of the path. In preferredembodiments of this aspect of the invention, the splicing surface has alength along the path at least equal to a plurality of widths of theweb; the apparatus further includes barrier means disposed along the webdelivery path immediately downstream from the splicing surface, thebarrier means including a slot through which the web passes; and theretarding means comprise a drum about which the web is trained and brakemeans for inhibiting rotation of the drum.

DETAILED DESCRIPTION OF THE DRAWINGS Other objects, features andadvantages of the invention will appear from the following descriptionof a preferred embodiment taken in conjunction with the accompanyingdrawings.

DESCRIPTION OF PARTICULAR PREFERRED EMBODIMENTS In FIG. 1 there is shownapparatus ofthe general type suitable to apply, to a length of pipe, aprotective coating in the form of a double wrapping of plastic web ortape. The pipe 10 enters the apparatus from the left (as shown inFIG. 1) and, while being conveyed from left to right is caused to rotatein a clockwise sense (as viewed along the direction of travel of thepipe 10 and as shown by the curved arrow in FIG. 1). The individuallengths of pipe 10 are supplied to the apparatus with the trailing endof one length of pipe abutting the leading end of the succeeding lengthof pipe so that the wrapping operation proceeds continuously despite thediscrete nature of the pipe being wrapped.

The pipe first enters a cleaner 12 which may be of any conventionaldesign (e.g., a plurality of rotary cylindrical brushes having axesparallel to the pipe). The pipe 10 next enters a primer station 14 whereany conventional primer coating may be applied. The pipe 10 thenreceives a first layer of plastic web 16 supplied along a web deliverypath which makes an acute angle A with the pipe 10. The angle A and thewidth of the web 16 can be varied, as is well known, to provide a properoverlap of the turns of the web 16 on the pipe (e.g., a /3 overlap) forany given pipe diameter and rate of both translation and rotation. Thefirst web 16 is typically an 8 to mil thick polyethylene tape having a 2to 10 mil coating of adhesive. The tape is supplied from a supply roll18 supported on a spindle 20. The tape 16 passes through a splicingfacilitator indicated schematically at 22. The spindle 20 is mounted onarm 24 which is supported for rotation on a frame 26. A second spindle28 is also mounted on the arm 24 for supporting a second roll of tape30. After a manual start-up, the web 16 is drawn onto the pipe 10 by themotion of the pipe. As further described below, retarding means areprovided to maintain tension in the web 16 as it is delivered to thepipe 10.

. A second or outer plastic tape 32 is supplied from a roll 34 mountedon spindle 36. As with the first web 16, a standby'roll 38 is supportedon spindle 40. Both spindles are mounted on an arm 42. The arm ispivotally mounted for rotation upon a frame member 44. A splicingfacilitator 46 is provided along the web delivery path. The path makesan angle B (where B=A) with the pipe 10.

The tape 32 is typically a heavier (e.g., 40 mil) polyethylene tapewithout an adhesive backing. Adhesion is secured, as described in detailin the previously mentioned US. Pat. No. 3,700,520, by the extrusion ofa bead 48 of molten polyethylene along one edge of the tape 32 by a unit50.

To facilitate the high speed, uninterrupted coating of pipe 10, thewrapping with tape 16 and 32 is continuous despite the discontinuousnature of the pipe 10. A cut-back device 52 is provided along the pathof travel of the pipe 10 downstream of the wrapping-operation whichremoves the tape adjacent to, and overlapping, the leading and trailingends 54, 56, respectively, of the lengths of pipe.

Referring to FIG. 2, the pipe 10 is supported on eonveying apparatuswhich includes wheels (indicated at 58) for producing the necessaryrotation of the pipe 10 to draw the webs 16, 32 onto the pipe. For eachweb 16, 32, the frame 26, 44 (which supports both the arm 24, 42 and thesplicing facilitator 22, 46) is itself pivotally supported as at 60, 62so that the angles A and B may be varied as desired.

Referring now to the supply of tape 16, it will be seen that thefacilitator 22 includes a roller 64 and a pair of nip rolls 66, 68, theroller and the nip defining a straight horizontal segment of the webdelivery path. Disposed adjacent and immediately below that portion ofthe path is a web stabilizing splicing member 70, including a flat,upper, pressure-receiving surface 72, mounted on the frame 26. Thesurface 72 is elongated in the direction of travel of the web 16 andpreferably has a length of at least twelve inches. Immediatelydownstream of the member 70, there is provided a barrier means 74 in theform of a vertically disposed plate having a slot 76 therein alignedwith the path of the web between roller 64 and nip 66, 68. Downstream ofthe nip, the web is trained about drum 78 which includes an internalbraking device 80 of any conventional design. The outer surface 82 ofdrum 78 is coated with slip-resistant material such as rubber. Roller 84is disposed downstream of the drum 78 and aligns the web 16 for travelto the length of pipe 10. Rollers 64, 66, and 68 are coated with aconventional release material 4 to prevent excessive sticking of theadhesive layer of web 16.

The arm 24 which supports the spindles 20, 28 is rigidly affixed to asprocket 86. The sprocket 86 may be driven by a chain (not shown) sothat the orientation of spindles 20, 28 with respect to the roller 64may be reversed when desired, as further discussed below.

The splicing facilitator 46, associated with web 32, includes arectangular web enclosure 88 having a web entrance slot disposedadjacent nip rolls 90, 92 and a web exit slot disposed adjacent niprolls 94, 96. The enclosure 88 has a depth which is less than twice thewidth of the web 32 and a height and width sufficient to enclose aplurality of slack web loops 98. The enclosure 88 is constructed toprovide for the visual inspection of the loops 98 within the enclosure(e.g., it may have walls of transparent plastic, wire mesh, etc.). Amotor 100 is mounted on the enclosure 88 and is connected by a belt 102to drive the nip roll 90.

Rolls 104 and 106 are also mounted on the enclosure 88 and define a webpath between the supply roll 34 and the nip rolls 90, 92. A member 108is supported along the web path between the supply roll 34 and the roll104 and includes a surface 110 disposed adjacent and parallel to the webpath.

Rolls 112 and 114 define the web path between the nip rolls 94, 96 and alarge drum 116 having an internal brake 118 and an outer surface 120which comprises a slip-resistant material such as rubber. Roll 122defines the final length of path of the web 32 for proper delivery tothe pipe 10. The arm 42 is fixed to, a sprocket 124, which may berotated by means of a chain (not shown), for reversing the positions ofthe spindles 36 and 40 with respect to the roll 104.

The operation of the splicing facilitator 22 is as follows: After aninitial manual start-up, web 16 is continuously drawn by the translatingand rotating pipe 10 from the supply roll 18. The retarding influence ofthe drum 78 maintains the tension in the web 16 which is necessary forproper application to the pipe 10. In a typical wrapping operation, theweb 16 travels across the upper surface 72 of splicing member 70 at arate suffcient to permit a manual splice of the self-adhesive tape 16.The splice is achieved by manually unwinding a sufficient length of tapefrom the roll 30 so that the free end of that roll may be held above thepressure receiving surface 72 of the splicing member 70. With his otherhand, the operator merely severs the web 16 between the roll 64 and thesupply roll 18 (or, alternatively, waits until the roll 18 is exhaustedof web) and immediately presses the free end of roll 30 onto thetrailing portion of the web 16 as it travels across the stabilizingsurface 72 of splicing member 70. The adhesive incorporated on onesurface of the web forms an instant splice so that the supply of web 16to the pipe 10 may be continuous. The barrier 74 is provided to preventan accidental drawing of the operators hand, with the web 16, toward niprolls 66, 68. The barrier plate extends sufficiently (e.g.. three inchesor more) above the slot to effectively mask the rolls 66, 68. After thesplice is achieved. the orientations of spindles 20 and 28 may bereversed as discussed above and a fresh roll of tape mounted on spindle20 preparatory to the next splice.

The splicing facilitator 46 for web 32 also includes a drum (drum 116)for applying a retarding force to the web and a web accumulator whichcomprises the enclosure 88, the nip rolls 90, 92, and the motor 100.Shortly before the splicing-in of a fresh roll of tape 38 is necessary,the motor 100 is turned on to drive the nip rolls 90, 92 by means of thebelt 102. The drive speed is chosen to be substantially faster than therate at which the web 32 is being drawn onto the pipe 10. The overfeedof web thus causes the formation of slack web loops 98 within theenclosure 88 and upstream of the retarding drum 116. With visuallytransparent walls for the enclosure 88, the operator can determine whenthe enclosure 88 is substantially filled with loops 98 and at that pointturn off the motor 100.

The web will then be supplied to the pipe from the excess supply withinthe enclosure 88, while the web upstream of the enclosure 88, includingthat adjacent 110, will remain stationary, and thus be stabilized". Thisstabilization of the web 32 is necessary to achieve an adequate splicesince, it will be recalled, the web 32 is not self-adhesive. With anadequately sized enclosure 88 (depending, of course, on the rate atwhich the web 32 is supplied to the pipe 10) substantial periods of time(e.g., up to a minute) may be provided, during which the trailingportion of web 32 is stabilized and stationary upstream of the roll 104so that a splice can be accomplished by severing the web 32, unrollingthe web from roll 38 a sufficient amount to reach the severed end of theweb and making a splice in any conventional fashion (e.g., using a smallpiece of adhesive tape such as tape 16). The splice may be achievedusing the surface 110 to facilitate the splicing operation. With anappropriately sized enclosure 88, however, there is adequate time forperforming a manual splice even without a facilitating surface such assurface 110.

After the splice has been completed, the location of spindles 36, 40 maybe reversed. Upon exhaustion of the supply of web within the enclosure88, the unwinding of web from the on-line supply roll will resume.

While particular embodiments have been described in detail, otherembodiments are within the scope of the invention and the followingclaims.

l claim:

1. In a stationary machine which applies a selfadhesive web as an outercoating to a length of moving pipe, the web being applied under tension,the machine including a web supply spindle and means defining a webdelivery path from said spindle to said length of pipe, the improvementcomprising retarding means disposed along said delivery pathintermediate said spindle and said length of pipe operative to exert aretarding force on the web delivered to said length of pipe,

and a splicing member including a splicing surface supported along saidweb delivery path intermediate said spindle and said retarding means,said surface being elongated in the direction of said path.

2. The improvement of claim 1 wherein said surface has a length alongsaid path at least equal to about 12 inches.

3. The improvement as claimed in claim 1 further including barrier meansdisposed along said web delivery path immediately downstream from saidsurface, said barrier means including a slot through which said webpasses.

4. The improvement as claimed in claim 3 wherein said barrier meanscomprise a plate having a slot therein for the passage of webtherethrough and extending in a directiongenerally perpendicular to saidsurface for a distance of at least 3 inches.

5. The improvement as claimed in claim 1 wherein said retarding meanscomprise a drum about which said web is trained and brake means forinhibiting rotation of said drum.

6. The improvement as claimed in claim 5 wherein said drum has aslip-resistant outer surface.

7. The improvement as claimed in claim 6 wherein said outer surface isrubber.

8. In a stationary machine which applies an outer coating to a length ofmoving pipe, the coating comprising an inner self-adhesive web and anouter non-self adhesive web, each web being applied under tension, themachine including respective web supply spindles and means defining webdelivery paths from said spindles to said length of pipe, theimprovement comprisfor each web, retarding means disposed along said webdelivery path intermediate said spindle and said length of pipeoperative to exert a retarding force on the web delivered to said lengthof pipe, and a splicing surface disposed along said web delivery pathintermediate said spindle and said retarding means;

said surface associated with said inner web being elongated in thedirection of said path; and

a web storage unit associated with said outer web comprising a webcontainer for storing slack web and web drive means upstream along saidweb deliver path of said container selectively operative to supply webto said container at a rate which is faster than the rate which said webis applied to said length of pipe.

1. In a stationary machine which applies a self-adhesive web as an outercoating to a length of moving pipe, the web being applied under tension,the machine including a web supply spindle and means defining a webdelivery path from said spindle to said length of pipe, the improvementcomprising retarding means disposed along said delivery pathintermediate said spindle and said length of pipe operative to exert aretarding force on the web delivered to said length of pipe, and asplicing member including a splicing surface supported along said webdelivery path intermediate said spindle and said retarding means, saidsurface being elongated in the direction of said path.
 2. Theimprovement of claim 1 wherein said surface has a length along said pathat least equal to about 12 inches.
 3. The improvement as claimed inclaim 1 further including barrier means disposed along said web deliverypath immediately downstream from said surface, said barrier meansincluding a slot through which said web passes.
 4. The improvement asclaimed in claim 3 wherein said barrier means comprise a plate having aslot therein for the passage of web therethrough and extending in adirection generally perpendicular to said surface for a distance of atleast 3 inches.
 5. The improvement as claimed in claim 1 wherein saidretarding means comprise a drum about which said web is trained andbrake means for inhibiting rotation of said drum.
 6. The improvement asclaimed in claim 5 wherein said drum has a slip-resistant outer surface.7. The improvement as claimed in claim 6 wherein said outer surface isrubber.
 8. In a stationary machine which applies an outer coating to alength of moving pipe, the coating comprising an inner self-adhesive weband an outer non-self adhesive web, each web being applied undertension, the machine including respective web supply spindles and meansdefining web delivery paths from said spindles to said length of pipe,the improvement comprising, for each web, retarding means disposed alongsaid web delivery path intermediate said spindle and said length of pipeoperative to exert a retarding force on the web delivered to said lengthof pipe, and a splicing surface disposed along said web delivery pathintermediate said spindle and said retarding means; said surfaceassociated with said inner web being elongated in the direction of saidpath; and a web storage unit associated with said outer web comprising aweb container for storing slack web and web drive means upstream alongsaid web deliver path of said container selectively operative to supplyweb to said container at a rate which is faster than the rate which saidweb is applIed to said length of pipe.